System and method for managing air from a cooktop

ABSTRACT

A kitchen ventilation system includes a sensor for detecting a chemical composition over an active zone of a cooktop. The system also includes an air moving device for displacing air including the chemical composition and an air flow direction control device for directing air displaced by the air moving device between exhaust and recirculation flow paths. A control circuitry is coupled to the sensor, to the air moving device and to the air flow direction control device for regulating operation of the air moving device and a position of the air flow direction control device based upon signals from the sensor.

BACKGROUND

The invention relates generally to systems for moving, treating andventing air in a space and, more particularly, to ventilating systems,such as those used with cooktops and the like.

Various types of systems have been designed and are in use for ventingand circulating air in environments such as kitchens. In general,ventilating and circulating systems serve to remove and recirculate, orto vent air from above or adjacent to a stove, cooktop or other device.The systems draw in air and vapors that may be laden with grease andodors, clean the air, and either recirculate the air to the room or ventthe air to the outside. Because the vapors and hot air rise, the systemsare typically situated above the cooking surface and associated with ahood, although other systems may be located adjacent to or even in thecooking system itself.

Such kitchen ventilating systems typically include, without limitation,fans, filters for grease removal and a control system. Typical kitchenventilating systems are designed to cover the whole area of a cookingapparatus with at least one centrifugal fan and a set of filters forgrease removal. However, in many cases a user of the cooking apparatusperforms the cooking activities using only a limited number of burnersamong the available number of burners in the cooking apparatus. Thekitchen ventilating systems covering the whole area of the cookingapparatus in such cases distribute the static pressure developed by thefan on the entire area of the cooking apparatus, thus requiring highercapacity fans for effective capture of the vapors over the cookingsurface. Such conventional systems thus result in relatively high energyconsumption and noise generation.

In a conventional kitchen ventilating apparatus limited flexibility isprovided to the users in terms of setting the apparatus in exhaust orventilation modes. Moreover, while certain systems permit some degree ofregulation of the speed of the fan, at the fan can most often be set toonly one of typically available two or three pre determined speedoptions. However, usage of these limited options may result insituations where insufficient or excess fan power is delivered,resulting in either poor capture of flumes or excess energy consumptionand noise generated, respectively.

Accordingly, it would be desirable to develop a system that senses theactive zone of a cooking apparatus and the target air constituents to beremoved from the air. It would also be advantageous to provide a systemthat could utilize this information to operate the system in a mosteffective manner, while maintaining the flexibility to the user foroperation of the system.

BRIEF DESCRIPTION

Briefly, in accordance with one aspect of the present invention akitchen ventilation system includes a sensor for detecting a chemicalcomposition over an active zone of a cooktop. The system also includesan air moving device for displacing air including the chemicalcomposition and an air flow direction control device for directing airdisplaced by the air moving device between exhaust and recirculationflow paths. A control circuitry is coupled to the sensor, to the airmoving device and to the air flow direction control device forregulating operation of the air moving device and a position of the airflow direction control device based upon signals from the sensor.

In accordance with another aspect of the present invention, a method forventilating air over an active side of a cooktop comprises sensing aside of a cooktop on which cooking is performed and controlling an airmoving device for displacing air from the cooktop and an air flowdirection control device for directing air displaced by the air movingdevice between exhaust and recirculation flow paths based upon thesensed side of the cooktop.

DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a diagrammatical representation of a ventilation system fortreating air adjacent to a cooktop in accordance with aspects of thepresent technique;

FIG. 2 depicts an exemplary display system and user inputs of a kitchenventilation system of the type shown in FIG. 1;

FIG. 3 is a diagrammatical representation of a kitchen ventilationsystem of the type shown in FIG. 1, housing the components over acooktop;

FIG. 4 is a block diagram of steps in exemplary control logic foridentifying the air circulation mode of an air flow direction controldevice in a kitchen ventilating system based on an air qualityparameter;

FIG. 5 is a block diagram representing exemplary logic for identifyingan operating system for a kitchen ventilating system based upon inputduct parameters and installation site parameters;

FIG. 6 is a graphical representation of exemplary settings available fora kitchen ventilating system of the type shown in FIG. 1, based uponinput duct parameters;

FIG. 7 is a graphical representation of exemplary settings available fora kitchen ventilating system of the type shown in FIG. 1, based uponinstallation site parameters;

FIG. 8 is a graphical representation of a set of exemplary operatingpoints available for a kitchen ventilating system of the type shown inFIG. 1, based upon input duct parameters and installation siteparameters;

FIG. 9 is a diagrammatic illustration of an exemplary air circulationmode of an air flow direction control device for a kitchen ventilatingsystem of FIG. 1;

FIG. 10 is a diagrammatic illustration of another air circulation modeof an air flow direction control device for a kitchen ventilating systemof FIG. 1;

FIG. 11 depicts the flow of information on internal references andinputs for a controller of a control circuitry of a kitchen ventilationsystem of the type illustrated in the previous figures; and

FIG. 12 represents an exemplary overview of the display system and thepower output from a controller of a control circuitry of the kitchenventilation system illustrated in the previous figures.

DETAILED DESCRIPTION

Referring now to FIG. 1, a kitchen ventilating system 10 generallyincluding a series of components disposed in a ventilating systemhousing 12. In the illustrated embodiment, the housing 12 includessensors 14 for detecting certain vapors and their constituents, and anair moving device 16, such as a fan for displacing air. An air flowdirection control device 18 controls the mode of operation of the systemby directing air displaced by the device 16. An air purification device20 may be included for cleaning or purifying the displaced air. Alsoillustrated in FIG. 1 are motors 22 and 24 that drive the air movingdevice 16, and the air flow direction control device 18, respectively.Finally, a UV source 26 may be provided for eliminating certain odors,as described below.

The housing 12 and its housed components are shown disposed over acooktop 28 for treating air adjacent to a cooktop 28 of a cookingappliance such as a gas stove, a gas oven and so forth. In general,vapors, odors, chemical compositions, and so forth will be created ororiginate from one of more active zones 30 of the cooktop 28, typicallythose over or with which cooking operations are performed. The sensor 14is configured to receive inputs 32 regarding the characteristics of theair above and adjacent to an active zone 30 of the cooktop 28. It shouldbe noted that, as used herein, the term “active zone” includes an areaover the cooktop where the cooking fumes, vapors, smoke and combustionbyproducts are generated as a result of cooking activities of a user ofthe cooking apparatus. Typically, the inputs 32 received by the sensor14 includes a chemical composition 34 of the air above the active zone30 of the cooktop 28.

Furthermore, the sensor 14 may be configured to capture temperature 36and humidity 38 data of the air above and adjacent to the active zone 30of the cooktop 28 as a part of the input 32. As discussed in greaterdetail below, such data is used by control circuitry 40 for regulatingthe operation of the air moving device 16 and a position of the air flowdirection control device 18.

In one embodiment, the air moving device 16 receives signals related tocertain operating parameters (e.g., speed of a fan) from the controlcircuitry 40, for generating required static pressure by the air movingdevice 16. In another embodiment, the air flow direction control device18 receives signals from the control circuitry 40 and selects a positionof the air flow control device 18 for directing air displaced by the airmoving device 16 between exhaust and recirculation flow paths (e.g.,positions of a louver or diverting gate).

Further, air purification device 20 may be used for air purification byreducing the concentration of certain chemical compositions 34 of thedisplaced air through the air moving device 16. The air purificationdevice 20 according to this embodiment may include, but is notnecessarily limited to, an active device, a corona discharge device andan ultraviolet air purification device. In another embodiment, the airpurification device 20 may include a filter to facilitate odordestruction and microorganism destruction of the displaced air by theair moving device 16. Alternatively, a UV-based system with the UVsource 26 may be used for the destruction of the odor generated from thecooktop 28 and for the removal of any microorganisms if present in theair above and adjacent to the cooktop 28. Moreover, a grease filter maybe used to capture grease entrained in the combustion byproducts fromthe cooking apparatus.

In operation, the sensor 14 detects the active zone 30 of the cookingapparatus and the target air constituents to be removed from the airabove the active zone 30 of the cooktop 28, and provides thisinformation to the control circuitry 40. In addition, the sensor 14 mayalso be configured to detect the UV intensity of the UV based odor andmicroorganism reduction system. This information may be utilized by thecontrol circuitry 40 for regulating the operation of the air movingdevice 16, the air flow direction control device 18 and the airpurification device 20 to maintain the desired air quality.

Control circuitry 40 may include an interface 42 for facilitatinginterface between the kitchen ventilation system components, and acontroller 44 powered by a power supply 48. The controller 44 may behard-wired and housed in a suitable exposed or covered enclosure fixedon or even within the kitchen ventilating system housing. Alternatively,the controller 44 may be placed in a remote location. Further, thecontroller 44 may receive and transmit signals pertaining to the statusof the air quality and corresponding control and display signalsremotely via means such as, infrared, radio frequency andelectromagnetic transmission signal transmission media. Additionally,the controller 44 may use the temperature 36 and humidity 38 dataacquired over the cooktop 28 via sensor 14 to compute temperature andhumidity-compensated response of the air quality sensor 14 to assess thechange in air quality on account of elements other than temperature 36and humidity 38.

In general, in a presently contemplated embodiment, the controller 44offers a momentary high power operation for a pre-determined time duringstart-up, and later changes to an optimum power mode of operation basedon air quality status. In addition, the controller 44 may have a set ofpredefined programs stored that can be individually executed by a userof the system.

In a present embodiment, the control circuitry 40 also includes memorycircuitry 46 for storing the pre-defined programs, internal references50 for the operation of the components of the system and so forth. Theinternal references 50 may include operating cycle set points 52,operating cycle timings 54, sensor look up tables 56 for the sensor 14,ventilation rate tables 58 for the air moving device 16, a timer 60, aninternal counter 62, and so forth. These references and devices may beutilized by the controller 44 for deciding the operating parameters forthe kitchen ventilating system 10. Further, these operating parametersare communicated as, or used to derive output signals 68 to the airmoving device 16, the air flow direction control device 18, and the airpurification device 20.

Such output signals, indicated collectively by reference numeral 68, aretransmitted from the controller 44 to the air moving device 16, the airflow direction control device 18 and the air purification device 20 toregulate operation of the system. Such output signals may include,without limitation, air moving device speed 70, air moving device status72, air flow direction control device status 74 and UV source status 76.The status of the above mentioned parameters may be made available to auser of the system via a display system 66 which will be discussedhereinafter. Also, the controller 44 is configured to receive userinputs 64 which may be used by the controller 44 for deciding theoperating parameters for the kitchen ventilating system 10.

FIG.2 illustrates an exemplary display system 66 and user inputs 64 of akitchen ventilation system of the type shown in FIG. 1. The displaysystem 66 may have different display options to indicate the status ofthe different components of the kitchen ventilation system 10. Forexample, an air moving device speed LED or numerical display 78 may beprovided that is indicative of the speed of the air moving device 16.Further, air quality sensitivity LED or display 80 may be provided todisplay the information about the quality of the air above the cooktop28 as sensed by the sensor 14. In addition, the display system 66 mayinclude a timer display 82, a power-on LED 86 and a “replace filter”display 84 to indicate the status of the filter used in the airpurification device 20.

In the illustrated embodiment, the user inputs 64 typically includesoperation state 88, air circulation mode selection 90, start or delayoption 92, operating cycle selection 94, lamp control option 96, airquality sensitivity level option 98, counter reset option 100, and soforth. The operation state 88 may set the kitchen ventilation system 10in either manual state or auto state. The air circulation mode 90includes settings for placing the air flow direction control device 18in exhaust or recirculation modes.

FIG. 3 represents, diagrammatically, a kitchen ventilation systemimplementation 102 with certain of the components discussed above overthe cooktop 28. In operation, sensor 14 receives the inputs 32 from theactive side 30 of the cooktop 28. Examples of such sensors for sensingthe air quality over the active side 30 of the cooktop 28 include,without limitation, heated metal oxide sensors, electro-chemical gassensors, pellistors, hot wire catalytic gas sensors, semiconductor gassensors, photo ionization smoke detectors, thermal conductivity type gassensors, ultrasonic gas sensors, UV flame sensors, IR temperaturesensors, heat flux sensors, air velocity sensors and so forth. Further,additional sensors for example, passive infrared (PIR) sensors may beused for detecting movement of any object in the installation location.The inputs 32 received by the sensor 14 are used by the controller 44for controlling and operating the components of the kitchen ventilationsystem 10. Furthermore, a grease filter 104 may be provided upstream ofthe sensor 14 and other components for grease removal from the airdisplaced with the air moving device 16.

Further, the location of the forward side 106 of the cooktop 28 and theaft side 108 of the cooktop 28 may also affect the operating parametersof the kitchen ventilating system 10. For example, the forward side 106of the cooktop 28 may be adjacent to a wall at the installation site.Alternatively, the forward side 106 of the cooktop 28 may be adjacent toan open space. Similarly, the aft side 108 of the cooktop 28 may beeither adjacent to a wall or adjacent to an open space. In addition tothe sensor 14, as described above, the air moving device 16 is alsocoupled to a sensor 114 for detecting the speed of the air moving device16. Further, a sensor 116 is coupled to the air flow direction controldevice 18 to detect the status (e.g., position) of the air flowdirection control device 18.

In the present embodiment, the controller 40 (see FIG. 1) is coupled tothe air moving device 16, air flow direction control device 18 and theair purification device 20. The controller 40 may use the inputs fromthe sensor 14 to operate the air moving device 16 to meet the requiredperformance parameters such as, required ventilation rate, requiredoperating speed and so forth. Moreover, based on the quality of the airabove the active side 30 of the cooktop 28, the air flow directioncontrol device 18 may be directed to a position for operating the airflow direction control device 18 in the exhaust or recirculation modes.Similarly, the controller 40 may implement closed loop control of theair moving device 16 and/or the air flow direction control device 18 byreference to inputs from sensors 114 and 116.

In another embodiment, the air purification device 20 is configured toreduce the content of certain chemical compositions 34 of the airdisplaced by the air moving device 16. Exemplary air purificationdevices 20 include, without limitation, an active device, a coronadevice, a UV air purification device and so forth. Moreover, the airpurification device 20 may have a filter to facilitate odor destructionand microorganism destruction of target air constituents or compositionsas sensed by the sensor 14 above and adjacent to the active side 30 ofthe cooktop 28. As will be appreciated by those skilled in the art, theodor and microorganism destruction may also be achieved through suitablefilters such as, activated carbon. Alternatively, other systems could beused, for example, a UV radiation system, catalytic oxidizer, ozonegenerator and so forth. As will be appreciated by those skilled in theart, the system may convert a part of the UV output from the UV basedodor and microorganism destruction system into visible light by using atransparent object with suitable phosphor coating. This may be used forilluminating the cooking space simultaneously along with odor andmicroorganism destruction.

The present configuration of the ventilating system offers an extremelyflexible platform for various types of logical operation of the systemcomponents based upon sensed, input and reference parameters of thetypes described above. For example, FIG. 4 illustrates exemplary controllogic 118, in accordance with but one aspect of the present techniques,for identifying the air circulation mode of the air flow directioncontrol device 18 in a kitchen ventilating system 10 based on an airquality parameter. The control logic begins with step 120, at which anair quality parameter is sensed via a sensor 14 over the cooktop 28. Theair quality parameter (AQ parameter) may be qualitative or quantitativeattributes of the target chemical composition 34 present in the airabove the active side 30 of the cooktop 28. The target chemicalcomposition 34 may include, without limitation, cooking fumes, vapors,smoke and combustion byproducts that are being generated as a result ofcooking activities of a user of the cooking apparatus. Next, at step 122the information about the AQ parameter is read and stored in the system.At step 124, the AQ parameter is compared with a reference value of theAQ parameter for calibrated pure (i.e. acceptable quality) air. If theAQ parameter sensed at step 120 is less than the desired value, thesystem returns to the entry point 120. However; if the AQ parametersensed at step 120 is more than the desired value, the system proceedsto the next step.

As shown in step 126, the system calculates a ratio of the AQ parameteras sensed on a first side (AQ1) of the active zone 30 of the cooktop 28and the second side (AQ2) of the active zone 30 of the cooktop 28.Further, at step 128, this ratio is compared with a first referencevalue of the ratio of the AQ parameters on the two sides. As shown atstep 130, if the calculated ratio is greater than the first referencevalue, the system sets the airflow direction control device 18 for firstside in exhaust mode and the sets the airflow direction control device18 for second side in re-circulation mode or in off mode; if thecalculated ratio is less than the first reference value, the systemproceeds to the step 132.

Next, at step 132 the calculated ratio of the AQ parameter on the twosides is compared with a second reference value of the ratio of the AQparameters on the two sides. At step 134, if the calculated ratio isless than second reference value, the system sets the airflow directioncontrol device 18 for first side in re-circulation mode or off mode andthe sets the airflow direction control device 18 for second side inexhaust mode. If the calculated ratio is greater than the secondreference value, the system proceeds to the step 136. At step 136, thesystem sets the airflow direction control device 18 for first side inexhaust mode and the sets the airflow direction control device 18 forsecond side in exhaust mode with reference to the limits 138 definingthe air circulation modes for the two sides of the air flow directioncontrol device 18.

As another example, the present system configuration affordssite-specific operation programming. As mentioned above, the varioussides and zones of the cooktop may be positioned adjacent to walls, openareas, and so forth. Similarly, the cooktop may be provided at specificheights above the cooktop, and the cooktop and system housing may be ofvarious sizes. FIG. 5 illustrates exemplary logic 140 for identifying anoperating configuration for the kitchen ventilating system 10 based uponsuch installation site parameters, as well as system criteria, such asinput duct parameters. The sequence of steps for selecting an operatingsystem based on the duct parameters is indicated generally by referencenumeral 142. In general, the sequence begins at step 144 where the ductlength is read by the system. Next, at step 146 the duct cross-sectionis made available to the system. At step 148 and step 150 the number ofbends in the duct and the type of filter used for the odor removal ofthe air are specified as input parameters. Further, at step 152 theventing option for the current duct is specified. In practice, thesevarious inputs may be provided manually at the time of system setup orconfiguration. At step 154 the operating configuration for the kitchenventilation system 10 based on the duct inputs and the internalreferences 50 as discussed above may be decided. Of course, more orfewer inputs may be considered in the configuration, as desired.

Following the selection of the operating configuration based on theinput duct parameters, the characteristics of the system based on theinstallation parameters are identified in accordance with the exemplarystep sequence 162. In general, the sequence begins at step 164 where thewidth of the hood is read by the system. At step 166 and step 168 theroom dimensions to define the volume and the installation location arespecified as input parameters respectively. Further, at step 170 andstep 172 the inputs regarding the height of the system above the cooktopand the type of the fuel used for the cooking apparatus are specifiedrespectively. Here again, such inputs may be provided manually at thetime of setup or configuration of the system. At step 174 the operatingparameters for the kitchen ventilation system 10 based on theinstallation site parameters may be decided. Here again, more or fewerof these exemplary factors may be considered for system configuration.

FIG. 6 illustrates a graphical representation 156 of exemplary settingsavailable for a kitchen ventilating system of the type shown in FIG. 1,based upon input duct parameters, and the various other factorsdiscussed above. Typically, the system settings are available based onrequired air static pressure 158 and required flow rate (e.g., in cubicfeet per minute, CFM, or cubic meters per minute) or the air velocity160 from the plurality of reference settings 156 available for thesystem. FIG. 7 illustrates a graphical representation of the referencecurves 176 that may be used for deciding the operating system based onthe installation site parameters. In general the system settings areavailable based on required air static pressure 178 and required airflow rate or the air velocity 180 from the plurality of referencesettings 176 available for the system.

In the present embodiment illustrated in FIG. 8 the operating system andthe settings for the system based on the input duct parameters and theinstallation site parameters may be decided by combining the response ofthe settings of FIG. 6 and FIG. 7. The system settings for the operatingpoint are selected from a plurality of reference settings 184 based onthe static pressure 186 and the flow rate or velocity 188 of thecombined response. Once determined, the system may be set to operate inaccordance with the selected curves, which may be stored in thereference settings discussed above, thus configuring the systemspecifically to the installation.

FIG. 9 and FIG. 10 represent exemplary air circulation modes 190 of anair flow direction control device 18 for a kitchen ventilating system ofFIG. 1. Typically, the air flow direction control device 18 is disposedupstream of the air moving device 10 in a location 194 within thehousing 12 of the kitchen ventilating system 10. As noted above, thetarget air above the active side 30 of the cooktop 28 is displaced bythe air moving device 16. FIGS. 9 and 10 illustrate the air movingdevice 16 in somewhat greater detail as a fan having an inlet 196 and anoutlet 198 of the air moving device 16. Subsequently, based on thesignals received from the control circuitry 40 (see FIG. 1), the air maybe directed in the flow direction 200 as shown in FIG. 9 by placing theair flow direction control device 16 in a first position 110 to operatethe air flow direction control device 16 in an exhaust mode 192.Alternatively, as shown in FIG. 10, the air may be directed in the flowdirection 204 by placing the air flow direction control device 16 in asecond position 112 to operate the air flow direction control device 16in a re-circulation mode 202.

FIG. 11 depicts the flow of information 206 of internal references andinputs for the controller 44 of the control circuitry 40 of the kitchenventilation system 10 for performing control operations of the typediscussed above. The controller 44 receives the sensor inputs 208 fromthe air above cooktop 28, air moving device 16, air flow directioncontrol device 18 and the air purification device 20. The sensor inputs208 may include, without limitation, chemical composition 34 of thetarget air, heat measurements 210, temperature data 36, humidity data38, light intensity of the lamp 212, PIR motion of PIR sensor 214, UVintensity 216 of the UV source 26, pressure difference 218 for thefilter used for the air purification device 20 and RPM 220 of the airmoving device 16.

Further, as discussed above, the controller 40 may have a set ofinternal references 50 to control and operate the various components ofthe kitchen ventilation system 10. The controller 40 may also receiveinputs 64 from a user of the system for providing flexibility to theuser for operating the system.

FIG. 12 illustrates an exemplary overview 222 of the display system 66,the power output 224 from the controller 44, and the output signals 68from the controller 44 of the control circuitry 40 of the kitchenventilation system 10. The display system 66 includes, withoutlimitation, air moving device speed LED or display 78, AQ sensitivityLED or display 80, timer display 82, replace filter display 84 and poweron LED or display 86.

In the present embodiment, the power output 224 from the controller 44may include, without limitation, power output for air moving device 226,power output for air flow direction control device 228, power output forexcitation of sensors 230, power output for lamp 232 and power outputfor the UV system 234. Further, the signal output 68 transmitted fromthe controller 44 to the components of the kitchen ventilation system 10may include air moving device speed 70, air moving device status 72, airflow direction control device status 74, UV source status and so forth.

As will be appreciated by those skilled in the art, the present systemthus allows for closed loop control for managing air above a cooktop 28based on assessing the status of air quality by monitoring the level ofthe target constituents present in the air. The system is typicallyinstalled and used near a cooking appliance such as, cooking range,oven, or grill for moving and treating cooking fumes, vapors, smoke andother combustion products resulting from the cooking activities of auser of the system. Further, the system as described in the variousembodiments hereinabove, uses the response of the air quality sensors togenerate suitable control and display signals to facilitate controllingvarious elements such as, without limitation, operating speed and statusof the air moving device 14, opening or closing of the air flowdirection control device 16, activation and control of odor removalsystem and so forth.

In addition, the system also provides flexibility to a user for decidingthe operating parameters by specifying certain user-defined inputs. Asnoted above, the system operates at an operating point determined by thesensing and control system which includes parameters such as, operatingspeed, operating duration and so forth, thus reducing the acoustic noiseof the system during operation. Similarly, the system provides a veryflexible platform that may be specifically adapted to the configurationand aspects of the site in which the system is installed to provideoptimum performance.

The various aspects of the methods described hereinabove haveapplications in other environments for managing air. The embodimentsdescribed hereinabove can be used in the heating, ventilating and airconditioning area for managing air and maintaining required aircharacteristics in a space for human occupancy. The techniques may alsobe employed in a variety of appliances for example, a refrigeratordeodorizing system may be controlled using a sensor to detect foododors, a clothes washing machine may be controlled by sensing a targetcompound that may be an ingredient of the washing agent to evaluate theoptions for the operation of the washing machine and so forth.

While only certain features of the invention have been illustrated anddescribed herein, many modifications and changes will occur to thoseskilled in the art. It is, therefore, to be understood that the appendedclaims are intended to cover all such modifications and changes as fallwithin the true spirit of the invention.

1. A kitchen ventilation system comprising: a sensor for detecting achemical composition over an active zone of a cooktop; an air movingdevice for displacing air including the chemical composition; an airflow direction control device for directing air displaced by the airmoving device between exhaust and recirculation flow paths; and controlcircuitry coupled to the sensor, to the air moving device and to the airflow direction control device for regulating operation of the air movingdevice and a position of the air flow direction control device basedupon signals from the sensor.
 2. The system of claim 1, wherein thechemical composition is selected from the group comprising of cookingfumes, vapors, smoke and combustion byproducts.
 3. The system of claim1, wherein the sensor comprises at least one of a heated metal oxide gassensor, an electro-chemical gas sensor, pellistors, a hot wire catalyticgas sensor, a semiconductor gas sensor, a photo ionization smokedetectors, a thermal conductivity type gas sensor, an ultrasonic gassensor, a UV flame sensor, an IR temperature sensor, a heat flux sensorand a air velocity sensor.
 4. The system of claim 1, wherein the sensoris further configured to acquire temperature and humidity data over anactive zone of the cooktop.
 5. The system of claim 1, wherein thecontrol circuitry comprises of a controller with a set of pre definedstored programs that can be individually executed by a user of thesystem.
 6. The system of claim 1, wherein the control circuitrycomprises of a controller configured to compute temperature and humiditycompensated response of an air quality sensor based upon temperature andhumidity data acquired over the active zone of the cooktop.
 7. Thesystem of claim 1, wherein the control circuitry comprises of acontroller that receives and transmits signals pertaining to the statusof air quality and corresponding control and display signals remotelythrough at least one of infrared, radio frequency and electromagnetictransmission modes.
 8. The system of claim 1, further comprising an airpurification device for reducing content of the chemical composition inthe displaced air.
 9. The system of claim 8, wherein the airpurification device is an active device.
 10. The system of claim 8,wherein the air purification device is a corona discharge device. 11.The system of claim 8, wherein the air purification device is a UV airpurification device.
 12. The system of claim 8, wherein the airpurification device comprises a filter to facilitate odor destructionand microorganism destruction.
 13. The system of claim 8, wherein theair purification device comprises grease filter.
 14. A method forventilating air over an active side of a cooktop comprising: sensing aside of a cooktop on which cooking is performed; controlling an airmoving device for displacing air from the cooktop and an air flowdirection control device for directing air displaced by the air movingdevice between exhaust and recirculation flow paths based upon thesensed side of the cooktop.
 15. The method of claim 14, wherein sensinga side of a cooktop comprises detecting a chemical composition over thecooktop through a sensor.
 16. The method of claim 15, wherein thechemical composition is selected from a group comprising of cookingfumes, vapors, smoke and combustion byproducts.
 17. The method of claim15, wherein the sensor comprises at least one of a heated metal oxidegas sensor, an electro-chemical gas sensor, pellistors, a hot wirecatalytic gas sensor, a semi-conductor gas sensor, a photo ionizationsmoke detectors, a thermal conductivity type gas sensor, an ultrasonicgas sensor, a UV flame sensor, an IR temperature sensor, a heat fluxsensor and a air velocity sensor.
 18. The method of claim 14, whereinsensing a side of a cooktop further comprises acquiring temperature andhumidity data over an active zone of the cooktop.
 19. The method ofclaim 14, wherein the controlling step comprises of receiving andtransmitting signals pertaining to the status of air quality andcorresponding control and display signals remotely through at least oneof infrared, radio frequency and electromagnetic transmission modes. 20.The method of claim 14, wherein the controlling step comprises executinga set of pre defined programs stored in a controller by a user.
 21. Themethod of claim 14, further comprising purifying of the air over theactive side of the cooktop through an air purification device byreducing content of the chemical composition sensed by the sensor overthe cooktop.
 22. A kitchen ventilation system comprising: a sensor fordetecting an operating parameter of a cooktop; an air moving device fordisplacing air from the cooktop; an air flow direction control devicefor directing air displaced by the air moving device between exhaust andrecirculation flow paths; and control circuitry coupled to the sensor,to the air moving device and to the air flow direction control devicefor regulating operation of the air moving device and a position of theair flow direction control device based upon signals from the sensor,wherein operation of the control circuitry is configurable based uponsite-specific factors of a site in which the ventilation system isinstalled.
 23. The system of claim 22, wherein the sensor comprises atleast one of a heated metal oxide gas sensor, an electro-chemical gassensor, pellistors, a hot wire catalytic gas sensor, a semi-conductorgas sensor, a photo ionization smoke detectors, a thermal conductivitytype gas sensor, an ultrasonic gas sensor, a UV flame sensor, an IRtemperature sensor, a heat flux sensor and a air velocity sensor. 24.The system of claim 22, wherein the operating parameter is a chemicalcomposition of air over an active zone of the cooktop.
 25. The system ofclaim 24, wherein the chemical composition is selected from a groupcomprising of cooking fumes, vapors, smoke and combustion byproducts.25. The system of claim 22, wherein the operating parameter istemperature of air over the active zone of the cooktop.
 26. The systemof claim 22, wherein the operating parameter is humidity of air over theactive zone of the cooktop.
 27. The system of claim 22, wherein thesite-specific factors include at least one of hood width, sitedimensions, installation location, height above the cooktop and type offuel.
 28. The system of claim 22, further comprising an air purificationdevice for reducing content of the chemical composition in the displacedair.
 29. The system of claim 28, wherein the air purification device isan active device.
 30. The system of claim 28, wherein the airpurification device is a corona discharge device.
 31. The system ofclaim 28, wherein the air purification device is a UV air purificationdevice.
 32. The system of claim 28, wherein the air purification devicecomprises a filter to facilitate odor destruction and microorganismdestruction.
 33. The system of claim 28, wherein the air purificationdevice comprises grease filter.
 34. A kitchen ventilation systemcomprising: a sensor for detecting an operating parameter of a cooktop;an air displacement system including an air moving device for displacingair from the cooktop, and an air flow direction control device fordirecting air displaced by the air moving device between exhaust andrecirculation flow paths; and control circuitry coupled to the sensorand to the air displacement system for regulating operation of the airdisplacement system based upon signals from the sensor and uponcharacteristics of the air displacement system to reduce acoustic noiseof the ventilation system during operation.
 35. The system of claim 34,wherein the sensor comprises at least one of a heated metal oxide gassensor, an electrochemical gas sensor, pellistors, a hot wire catalyticgas sensor, a semi-conductor gas sensor, a photo ionization smokedetectors, a thermal conductivity type gas sensor, an ultrasonic gassensor, a UV flame sensor, an IR temperature sensor, a heat flux sensorand a air velocity sensor.
 36. The system of claim 34, wherein theoperating parameter is a chemical composition of air over an active zoneof the cooktop.
 37. The system of claim 36, wherein the chemicalcomposition is selected from a group comprising of cooking fumes,vapors, smoke and combustion byproducts.
 38. The system of claim 34,wherein the operating parameter is temperature of air over the activezone of the cooktop.
 39. The system of claim 34, wherein the operatingparameter is humidity of air over the active zone of the cooktop. 40.The system of claim 34, wherein the characteristics of the airdisplacement system comprises a set of operating set point referencesfor the air displacement system.
 41. The system of claim 34, wherein thecharacteristics of the air displacement system comprises a set ofoperating cycle timing references for the air displacement system. 42.The system of claim 34, wherein the characteristics of the airdisplacement system comprises a ventilation rate look-up table for theair displacement system.